jto 1.4.0

Convert json object to dataclass and vice versa

JTO Converter

Description

Convert json object to dataclass and vice versa. This package also provides tool for converting json object to dataclass template.

Requirements

Required structure of dataclass field

field_name: Optional[FieldType] = field(default=Undefined, metadata={'name': 'json_field_name', 'required': False, 'validate': validate_function})

• field_name [required] can be any variable name.
• Optional [optional] indicates that the field is nullable.
• FieldType [required] should be strongly typed.
  For example in case of field containing the list it should look like this List[SomeClass]
• default [required] sets default field's value. Set to Undefined by default.
• name [required] is the name of the field in original json.
• required [required] marked True if the field is required in the provided json.
• validate [optional] is the function that validates the field's value. Validate function supports fields with simple types like str, int, float, bool and List of simple types. The function has one argument - field's value. It should return True if the value is valid and False otherwise. Example lambda function: lambda x: x > 0

Additional rules

• If dataclass field value set to Undefined then it will not be converted to json field
• If dataclass field type is not Optional then all dataclass fields with None values will not be converted to json fields

Examples

Convert json object to class objects

from dataclasses import dataclass, field
from typing import List, Optional

from jto import JTOConverter
from jto.undefined_field import Undefined

data = {
    "status": 200,
    "data": {
        "first": "qwer",
        "last": "qwer",
        "test": [
            {"f1": "1"},
            {"f1": "2"}
        ]
    }
}

@dataclass
class Test:
    f1: Optional[str] = field(default=Undefined, metadata={'name': 'f1', 'required': False})

@dataclass
class Data:
    first: Optional[str] = field(default=Undefined, metadata={'name': 'first', 'required': False, 'validate': lambda x: x == 'qwer'})
    last: Optional[str] = field(default=Undefined, metadata={'name': 'last', 'required': False})
    test: Optional[List[Test]] = field(default=Undefined, metadata={'name': 'test', 'required': False})

@dataclass
class Response:
    status: Optional[int] = field(default=Undefined, metadata={'name': 'status', 'required': False})
    data: Optional[Data] = field(default=Undefined, metadata={'name': 'data', 'required': False})


dataclass_object = JTOConverter.from_json(Response, data)
print(dataclass_object)

dataclass_object.status = None
json_object = JTOConverter.to_json(dataclass_object)
print(json_object)

Get class templates from json object

from jto.dataclass_generator import DataclassGenerator

data = {
    "status": 200,
    "data": {
        "first": "foo",
        "last": "bar",
        "struct": [
            {"f1": "1"},
            {"f1": "2"}
        ]
    }
}

classes = DataclassGenerator()
classes_str = classes.build_classes_string('Response', data)
print(classes_str)